Clutch and gear arrangement for a front wheel drive vehicle

ABSTRACT

A front wheel drive transmission is provided having an input member, an output member, four planetary gear sets, a plurality of coupling members and a plurality of torque transmitting devices. Each of the planetary gear sets includes a sun gear member, a planet carrier member, and a ring gear member. The torque transmitting devices include clutches and brakes arranged within a transmission housing. Each of the clutches and the brakes are located within specific areas defined by the planetary gear sets and the housing walls.

FIELD

The invention relates generally to a multiple speed transmission havinga plurality of planetary gear sets and a plurality of torquetransmitting devices and more particularly to a transmission configuredfor a front wheel drive vehicle having eight or more speeds, five torquetransmitting devices, and four planetary gear sets.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may or may not constitute priorart.

A typical multiple speed transmission uses a combination of a pluralityof torque transmitting mechanisms, planetary gear arrangements and fixedinterconnections to achieve a plurality of gear ratios. The number andphysical arrangement of the planetary gear sets, generally, are dictatedby packaging, cost and desired speed ratios.

While current transmissions achieve their intended purpose, the need fornew and improved transmission configurations which exhibit improvedperformance, especially from the standpoints of efficiency,responsiveness and smoothness and improved packaging, primarily reducedsize and weight, is essentially constant. Accordingly, there is a needfor an improved, cost-effective, compact multiple speed transmission.

SUMMARY

In one aspect of the present invention, a transaxle is provided having atransmission input member, a transmission output member, a plurality ofplanetary gear sets, and a plurality of torque-transmitting mechanisms.

In another aspect of the present invention, the transaxle includes aninput member, an output member, a housing having a first wall, a secondwall, and a third wall extending between the first and second walls.First, second, third and fourth planetary gear sets are disposed withinthe housing, wherein the first planetary gear set is adjacent the firstwall, the third planetary gear set is adjacent second wall, the fourthplanetary gear set is adjacent the first planetary gear set and thesecond planetary gear set is between the fourth and third planetary gearsets. Each planetary gear set has a sun gear member, a ring gear member,and a planet carrier member supporting a plurality of planet gears eachconfigured to intermesh with both the sun gear member and the ring gearmember, and the sun gear member of the first planetary gear set ispermanently coupled to the sun gear member of the fourth planetary gearset, the ring gear member of the first planetary gear set is permanentlycoupled to the sun gear member of the second planetary gear set, thering gear member of the second planetary gear set is permanently coupledto the sun gear member of the third planetary gear set, the ring gearmember of the third planetary gear set is permanently coupled to theplanet carrier member of the fourth planetary gear set, the input memberis permanently coupled to the planet carrier member of the firstplanetary gear set, and the output member is permanently coupled to theplanet carrier member of the third planetary gear set.

The housing has a first area defined radially inward from an outerperiphery of the planetary gear sets and axially bounded by the firstwall and the first planetary gear set, a second area defined radiallyinward from the outer periphery of the planetary gear sets and axiallybounded by the first and fourth planetary gear sets, a third areadefined radially inward from the outer periphery of the planetary gearsets and axially bounded by the fourth and second planetary gear sets, afourth area defined radially inward from the outer periphery of theplanetary gear sets and axially bounded by the second and thirdplanetary gear sets, a fifth area defined radially inward from the outerperiphery of the planetary gear sets and axially bounded by the thirdplanetary gear set and the second wall, and a sixth area definedradially inward from the third wall and radially outward from the outerperiphery of the planetary gear sets and axially bounded by the firstwall and the second wall.

A first clutch is disposed in at least one of the third, fourth, andsixth areas, a second clutch is disposed in at least one of the second,third, fourth, and fifth areas, a third clutch is disposed in at leastone of the fourth, fifth and sixth areas, a first brake is disposed inat least one of the first, second, and sixth areas, and a second brakeis disposed in at least one of the first, second, third, fifth, andsixth areas.

In yet another aspect of the present invention, the first clutch isdisposed in the third area, the second clutch is disposed in the fourtharea, the third clutch is disposed in the fifth area, the first brake isdisposed in the first area, and the second brake is disposed in thethird area.

In yet another aspect of the present invention, a first clutch isdisposed in at least one of the first, third, fourth, and fifth areas, asecond clutch is disposed in at least one of the first, third, fourth,and fifth areas, a third clutch is disposed in at least one of thefirst, fourth, fifth and sixth areas, a first brake is disposed in atleast one of the first, second, fifth, and sixth areas, a second brakeis disposed in at least one of the first, second, third, fifth, andsixth areas,

In yet another aspect of the present invention, the first clutch isdisposed in the third area, the second clutch is disposed in the fourtharea, the third clutch is disposed in the fifth area, the first brake isdisposed in the second area, and the second brake is disposed in thesecond area.

In yet another aspect of the present invention, the transaxle includesan input member, an output member, a housing having a first wall, asecond wall, and a third wall extending between the first and secondwalls. First, second, third and fourth planetary gear sets are disposedwithin the housing, wherein the fourth planetary gear set is adjacentthe first wall, the third planetary gear set is adjacent second wall,the first planetary gear set is adjacent the fourth planetary gear setand the second planetary gear set is between the first and thirdplanetary gear sets. Each planetary gear set has a sun gear member, aring gear member, and a planet carrier member supporting a plurality ofplanet gears each configured to intermesh with both the sun gear memberand the ring gear member, wherein the sun gear member of the firstplanetary gear set is permanently coupled to the sun gear member of thefourth planetary gear set, the ring gear member of the first planetarygear set is permanently coupled to the sun gear member of the secondplanetary gear set, the ring gear member of the second planetary gearset is permanently coupled to the sun gear member of the third planetarygear set, the ring gear member of the third planetary gear set ispermanently coupled to the planet carrier member of the fourth planetarygear set, the input member is permanently coupled to the planet carriermember of the first planetary gear set, and the output member ispermanently coupled to the planet carrier member of the third planetarygear set.

The housing has a first area defined radially inward from an outerperiphery of the planetary gear sets and axially bounded by the firstwall and the fourth planetary gear set, a second area defined radiallyinward from the outer periphery of the planetary gear sets and axiallybounded by the fourth and first planetary gear sets, a third areadefined radially inward from the outer periphery of the planetary gearsets and axially bounded by the first and second planetary gear sets, afourth area defined radially inward from the outer periphery of theplanetary gear sets and axially bounded by the second and thirdplanetary gear sets, a fifth area defined radially inward from the outerperiphery of the planetary gear sets and axially bounded by the thirdplanetary gear set and the second wall, and a sixth area definedradially inward from the third wall and radially outward from the outerperiphery of the planetary gear sets and axially bounded by the firstwall and the second wall.

A first clutch is disposed in at least one of the third, fourth, andsixth areas, a second clutch is disposed in at least one of the third,fourth, and fifth areas, a third clutch is disposed in at least one ofthe third, fourth, fifth and sixth areas, a first brake is disposed inat least one of the first, second, and sixth areas, and a second brakeis disposed in at least one of the first, second, third, fifth, andsixth areas.

In yet another aspect of the present invention, the first clutch isdisposed in the fourth area, the second clutch is disposed in the fourtharea, the third clutch is disposed in the fifth area, the first brake isdisposed in the first area, and the second brake is disposed in thefirst area.

In yet another aspect of the present invention, the transaxle includesan input member, an output member, a housing having a first wall, asecond wall, and a third wall extending between the first and secondwalls. First, second, third and fourth planetary gear sets are disposedwithin the housing, wherein the fourth planetary gear set is adjacentthe first wall, the third planetary gear set is adjacent second wall,the second planetary gear set is adjacent the fourth planetary gear setand the first planetary gear set is between the second and thirdplanetary gear sets. Each planetary gear set has a sun gear member, aring gear member, and a planet carrier member supporting a plurality ofplanet gears each configured to intermesh with both the sun gear memberand the ring gear member, wherein the sun gear member of the firstplanetary gear set is permanently coupled to the sun gear member of thefourth planetary gear set, the ring gear member of the first planetarygear set is permanently coupled to the sun gear member of the secondplanetary gear set, the ring gear member of the second planetary gearset is permanently coupled to the sun gear member of the third planetarygear set, the ring gear member of the third planetary gear set ispermanently coupled to the planet carrier member of the fourth planetarygear set, the input member is permanently coupled to the planet carriermember of the first planetary gear set, and the output member ispermanently coupled to the planet carrier member of the third planetarygear set.

The housing has a first area defined radially inward from an outerperiphery of the planetary gear sets and axially bounded by the firstwall and the fourth planetary gear set, a second area defined radiallyinward from the outer periphery of the planetary gear sets and axiallybounded by the fourth and second planetary gear sets, a third areadefined radially inward from the outer periphery of the planetary gearsets and axially bounded by the first and second planetary gear sets, afourth area defined radially inward from the outer periphery of theplanetary gear sets and axially bounded by the first and third planetarygear sets, a fifth area defined radially inward from the outer peripheryof the planetary gear sets and axially bounded by the third planetarygear set and the second wall, and a sixth area defined radially inwardfrom the third wall and radially outward from the outer periphery of theplanetary gear sets and axially bounded by the first wall and the secondwall.

A first clutch is disposed in at least one of the second, fourth, andsixth areas, a second clutch is disposed in at least one of the second,third, and sixth areas, a third clutch is disposed in at least one ofthe fourth, fifth and sixth areas, a first brake is disposed in at leastone of the first, second, and sixth areas, and a second brake isdisposed in at least one of the first, second, fifth, and sixth areas.

In yet another aspect of the present invention, the first clutch isdisposed in the second area, the second clutch is disposed in the thirdarea, the third clutch is disposed in the fifth area, the first brake isdisposed in the first area, and the second brake is disposed in thefirst area.

In yet another aspect of the present invention, the transaxle includesan input member, an output member, a housing having a first wall, asecond wall, and a third wall extending between the first and secondwalls. First, second, third and fourth planetary gear sets are disposedwithin the housing, wherein the fourth planetary gear set is adjacentthe first wall, the first planetary gear set is adjacent second wall,the third planetary gear set is adjacent the fourth planetary gear setand the second planetary gear set is between the third and firstplanetary gear sets, each planetary gear set having a sun gear member, aring gear member, and a planet carrier member supporting a plurality ofplanet gears each configured to intermesh with both the sun gear memberand the ring gear member, and wherein the sun gear member of the firstplanetary gear set is permanently coupled to the sun gear member of thefourth planetary gear set, the ring gear member of the first planetarygear set is permanently coupled to the sun gear member of the secondplanetary gear set, the ring gear member of the second planetary gearset is permanently coupled to the sun gear member of the third planetarygear set, the ring gear member of the third planetary gear set ispermanently coupled to the planet carrier member of the fourth planetarygear set, the input member is permanently coupled to the planet carriermember of the first planetary gear set, and the output member ispermanently coupled to the planet carrier member of the third planetarygear set.

The housing has a first area defined radially inward from an outerperiphery of the planetary gear sets and axially bounded by the firstwall and the fourth planetary gear set, a second area defined radiallyinward from the outer periphery of the planetary gear sets and axiallybounded by the fourth and third planetary gear sets, a third areadefined radially inward from the outer periphery of the planetary gearsets and axially bounded by the third and second planetary gear sets, afourth area defined radially inward from the outer periphery of theplanetary gear sets and axially bounded by the second and firstplanetary gear sets, a fifth area defined radially inward from the outerperiphery of the planetary gear sets and axially bounded by the firstplanetary gear set and the second wall, and a sixth area definedradially inward from the third wall and radially outward from the outerperiphery of the planetary gear sets and axially bounded by the firstwall and the second wall.

A first clutch is disposed in at least one of the second, third, andsixth areas, a second clutch is disposed in at least one of the third,fourth, and sixth areas, a third clutch is disposed in at least one ofthe third, fourth, fifth and sixth areas, a first brake is disposed inat least one of the first, second, and sixth areas, and a second brakeis disposed in at least one of the first, second, third, and sixthareas.

In yet another aspect of the present invention, the first clutch isdisposed in the second area, the second clutch is disposed in the fourtharea, the third clutch is disposed in the sixth area, the first brake isdisposed in the first area, and the second brake is disposed in thefirst area.

In yet another aspect of the present invention, the clutches and thebrakes are selectively engageable to establish at least eight forwardspeed ratios and at least one reverse speed ratio between the inputmember and the output member.

The transaxle of claim 1 wherein the first clutch is selectivelyengageable to interconnect the planet carrier member of the secondplanetary gear set with at least one of the planet carrier member of thethird planetary gear set and the output member, the second clutch isselectively engageable to interconnect at least one of the sun gearmember of the second planetary gear set and the ring gear member of thefirst planetary gear set with at least one of the sun gear member of thethird planetary gear set and the ring gear member of the secondplanetary gear set, the third clutch is selectively engageable tointerconnect at least one of the sun gear member of the third planetarygear set and the ring gear member of the second planetary gear set withat least one of the planet carrier member of the first planetary gearset and the input member, the first brake is selectively engageable tointerconnect at least one of the sun gear member of the first planetarygear set and the sun gear member of the fourth planetary gear set withthe housing, and the second brake is selectively engageable tointerconnect the ring gear member of the fourth planetary gear set withthe housing.

In yet another aspect of the present invention, the transaxle includes atransfer gear train having a first transfer gear intermeshed with asecond transfer gear, wherein the first transfer gear is rotatably fixedto the output member and the second transfer gear is rotatably fixed toan interconnecting shaft, a differential gear set for driving a pair ofroad wheels, a pinion gear rotatably fixed to the intermediate shaft,and an input differential gear in mesh with the pinion gear andconfigured to rotatably drive the differential gear set.

In yet another aspect of the present invention, the transaxle includes apower transfer assembly having a first transfer gear and a secondtransfer gear, wherein the first transfer gear is rotatably fixed to theoutput member and the second transfer gear is rotatably fixed to a driveshaft, a power transfer member rotatably coupling the first and secondtransfer gears for transferring rotational energy from the firsttransfer gear to the second transfer gear, a final drive planetary gearset coupled to the drive shaft for receiving a driving torque from thesecond transfer gear, and a differential gear set coupled to the finaldrive planetary gear set and to a pair of road wheels for receiving afinal drive rotational torque and transferring the final drive torque tothe pair of road wheels.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

FIG. 1A is a schematic diagram of a gear arrangement for a front wheeldrive transmission according to the principles of the present invention;

FIG. 1B is a chart showing the locations of the torque transmittingdevices for the arrangement of planetary gear sets of the transmissionshown in FIG. 1A, in accordance with the embodiments of the presentinvention;

FIG. 2A is another schematic diagram of a gear arrangement for a frontwheel drive transmission according to the principles of the presentinvention;

FIG. 2B is a chart showing the locations of the torque transmittingdevices for the arrangement of planetary gear sets of the transmissionshown in FIG. 2A, in accordance with the embodiments of the presentinvention;

FIG. 3A is another schematic diagram of a gear arrangement for a frontwheel drive transmission according to the principles of the presentinvention;

FIG. 3B is a chart showing the locations of the torque transmittingdevices for the arrangement of planetary gear sets of the transmissionshown in FIG. 3A, in accordance with the embodiments of the presentinvention;

FIG. 4A is another schematic diagram of a gear arrangement for a frontwheel drive transmission according to the principles of the presentinvention;

FIG. 4B is a chart showing the locations of the torque transmittingdevices for the arrangement of planetary gear sets of the transmissionshown in FIG. 4A, in accordance with the embodiments of the presentinvention;

FIG. 5A is another schematic diagram of a gear arrangement for a frontwheel drive transmission according to the principles of the presentinvention;

FIG. 5B is a chart showing the locations of the torque transmittingdevices for the arrangement of planetary gear sets of the transmissionshown in FIG. 5A, in accordance with the embodiments of the presentinvention;

FIG. 6 is a schematic diagram of a front wheel drive transaxlearrangement incorporating the gear arrangement of the transmission ofFIGS. 1A-5B, according to the principles of the present invention; and

FIG. 7 is another schematic diagram of a front wheel drive transaxlearrangement incorporating the gear arrangement of the transmission ofFIGS. 1A-5B, according to the principles of the present invention.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses.

Referring now to FIG. 1A, an embodiment of a front wheel drivemulti-speed or eight speed transmission is generally indicated byreference number 10. The transmission 10 is illustrated as a front wheeldrive or transverse transmission, though various other types oftransmission configurations may be employed. The transmission 10includes a transmission housing 12, an input shaft or member 14, anoutput shaft or member 16 and a gear arrangement 18. The input member 14is continuously connected to an engine (shown in FIGS. 6 and 7) or to aturbine of a torque converter (not shown). The output member 16 iscontinuously connected with a final drive unit (not shown) or transfercase (shown in FIGS. 6 and 7).

The gear arrangement 18 of transmission 10 includes a first planetarygear set 20, a second planetary gear set 22, a third planetary gear set24, and a fourth planetary gear set 26. The planetary gear sets 20, 22,24 and 26 are connected between the input member 14 and the outputmember 16.

In a preferred embodiment of the present invention, the planetary gearset 20 includes a sun gear member 20C, a ring gear member 20A, and aplanet carrier member 20B that rotatably supports a set of planet orpinion gears 20D (only one of which is shown). The sun gear member 20Cis connected to a first shaft or interconnecting member 42. The ringgear member 20A is connected for common rotation with a second shaft orinterconnecting member 44. The planet carrier member 20B is connectedfor common rotation with input shaft or member 14. The pinion gears 20Dare configured to intermesh with the sun gear member 20C and the ringgear member 20A.

The planetary gear set 22 includes a ring gear member 22A, a planetcarrier member 22B that rotatably supports a set of planet or piniongears 22D and a sun gear member 22C. The ring gear member 22A isconnected for common rotation with a third shaft or interconnectingmember 46. The sun gear member 22C is connected for common rotation withthe second shaft or interconnecting member 44. The planet carrier member22B is connected for common rotation with a fourth shaft orinterconnecting member 48. The pinion gears 22D are configured tointermesh with the sun gear member 22C and the ring gear member 22A.

The planetary gear set 24 includes a ring gear member 24A, a planetcarrier member 24B that rotatably supports a set of planet or piniongears 24D and a sun gear member 24C. The ring gear member 24A isconnected for common rotation with a fifth shaft or interconnectingmember 50. The sun gear member 24C is connected for common rotation withthe third shaft or interconnecting member 46. The planet carrier member24B is connected for common rotation with a sixth shaft orinterconnecting member 52 and also the output member 16. The piniongears 24D are configured to intermesh with the sun gear member 24C andthe ring gear member 24A.

The planetary gear set 26 includes a sun gear member 26C, a ring gearmember 26A, and a carrier member 26B that rotatably supports a set ofplanet or pinion gears 26D. The sun gear member 26C is connected forcommon rotation with the first shaft or interconnecting member 42. Thering gear member 26A is connected for common rotation with a seventhshaft or interconnecting member 54. The planet carrier member 26B isconnected for common rotation with the fifth shaft or interconnectingmember 50. The pinion gears 26D are configured to intermesh with the sungear member 26C and the ring gear member 26A.

The transmission 10 also includes a plurality of torque-transmittingmechanisms or devices including a first clutch 28, a second clutch 30, athird clutch 32, a first brake 34 and a second brake 36. The firstclutch 28 is selectively engagable to connect the fourth shaft orinterconnecting member 48 to the sixth shaft or interconnecting member52. The second clutch 30 is selectively engagable to connect the secondshaft or interconnecting member 44 with the third shaft orinterconnecting member 46. The third clutch 32 is selectively engagableto connect the third interconnecting member 46 with the input member 14.The first brake 34 is selectively engagable to connect the first shaftor interconnecting member 42 to the transmission housing 12 to restrictrotation of the first shaft or interconnecting member 42 relative to thetransmission housing 12. Finally, the second brake 36 is selectivelyengagable to connect the seventh interconnecting member 54 to thetransmission housing 12 to restrict rotation of the seventhinterconnecting member 54 relative to the transmission housing 12.

The transmission 10 is capable of transmitting torque from the inputshaft or member 14 to the output shaft or member 16 in at least eightforward torque ratios and one reverse torque ratio. Each of the forwardtorque ratios and the reverse torque ratio are attained by engagement ofone or more of the torque-transmitting mechanisms (i.e. first clutch 28,second clutch 30, third clutch 32, first brake 34 and second brake 36).Those skilled in the art will readily understand that a different speedratio is associated with each torque ratio. Thus, eight forward speedratios may be attained by the transmission 10.

The transmission housing 12 includes a first wall or structural member102, a second wall or structural member 104 and a third wall orstructural member 106. The third wall 106 interconnects the first andsecond walls 102 and 104 to define a space or cavity 110. The inputshaft or member 14 and output shaft or member 16 are supported by thesecond wall 104 by bearings 112. The planetary gear sets 20, 22, 24 and26 and the torque-transmitting mechanisms 28, 30, 32, 34 and 36 aredisposed within cavity 110. Further, the cavity 110 has a plurality ofareas or zones A, B, C, D, E, and F in which the plurality of torquetransmitting mechanisms 28, 30, 32, 34 and 36 will be specificallypositioned or mounted, in accordance with the preferred embodiments ofthe present invention.

As shown in FIG. 1A, Zone A is defined by the area or space bounded by:the first wall 102, planetary gear set 20, radially inward by areference line “L” which is a longitudinal line that is axially alignedwith the input shaft 14, and radially outward by a reference line “M”which is a longitudinal line that extends adjacent an outer diameter orouter periphery of the planetary gear sets 20, 22, 24 and 26. Whilereference line “M” is illustrated as a straight line throughout theseveral views, it should be appreciated that reference line “M” followsthe outer periphery of the planetary gear sets 20, 22, 24 and 26, andaccordingly may be stepped or non-linear depending on the location ofthe outer periphery of each of the planetary gear sets 20, 22, 24 and26. Zone B is defined by the area bounded by: planetary gear set 20, theplanetary gear set 26, radially outward by reference line “M”, andradially inward by reference line “L”. Zone C is defined by the areabounded by: the planetary gear set 26, the planetary gear set 22,radially outward by reference line “M”, and radially inward by referenceline “L”. Zone D is defined by the area bounded by: the planetary gearset 22, the planetary gear set 24, radially outward by reference line“M”, and radially inward by reference line “L”. Zone E is defined by thearea bounded by: the planetary gear set 24, the second end wall 104,radially outward by reference line “M”, and radially inward by referenceline “L”. Zone F is defined by the area bounded by: the first wall 102,the second wall 104, radially inward by reference line “M” and radiallyoutward by the third wall 106.

In the gear arrangement 18 of transmission 10 shown in FIG. 1A, theplanetary gear set 20 is disposed closest to the first wall 102, theplanetary gear set 24 is disposed closest to the second wall 104, theplanetary gear set 26 is adjacent the planetary gear set 20, and theplanetary gear set 22 is disposed between the planetary gear sets 24 and26. The torque-transmitting mechanisms are intentionally located withinspecific Zones in order to provide advantages in overall transmissionsize, packaging efficiency, and reduced manufacturing complexity. In theparticular example shown in FIG. 1A, the first clutch 28 is disposed inZone C, the second clutch 30 is disposed in Zone D, the third clutch 32is disposed in Zone E, the first brake 34 is disposed in Zone A, and thesecond brake 36 is disposed in Zone C.

However, the present invention contemplates other embodiments where thetorque-transmitting mechanisms 28, 30, 32, 34 and 36 are disposed in theother Zones. The feasible locations of the torque-transmittingmechanisms 28, 30, 32, 34 and 36 within the Zones are illustrated in thechart shown in FIG. 1B. The chart of FIG. 1B lists clutches and thebrakes in the left most column and the available zones to locate theclutch/brake in the top row. An “X” in the chart indicates that thepresent invention contemplates locating the clutch or brake in the zonelisted in the top row. For example, second brake 36 may be located inZones A, B, C, E, or F and first brake 34 may be located in zones A, B,or F.

Referring now to FIG. 2A, another embodiment of a transmission isgenerally indicated by reference number 100. The transmission 100 issimilar to transmission 10 and like components are indicated by likereference numbers. However, the transmission 100 includes an alternategear arrangement 118 where brakes 34 and 36 connect at a common locationat the third wall 106 and interconnect with the planetary gear sets 20and 26 on opposite sides than in the transmission 10. In addition, thesecond interconnecting member 44 connects with the planetary gear set 20on an opposite side than in the transmission 10 and the input member 14is disposed overtop and around the planetary gear set 20.

The torque-transmitting mechanisms are intentionally located withinspecific Zones in order to provide advantages in overall transmissionsize, packaging efficiency, and reduced manufacturing complexity. In theparticular example shown in FIG. 2A, the first clutch 28 is disposed inZone C, the second clutch 30 is disposed in Zone D, the third clutch 32is disposed in Zone E, and the first brake 34 and the second brake 36are disposed in Zone B.

However, the present invention contemplates other embodiments where thetorque-transmitting mechanisms 28, 30, 32, 34 and 36 are disposed in theother Zones. The feasible locations of the torque-transmittingmechanisms 28, 30, 32, 34 and 36 within the Zones are illustrated in thechart shown in FIG. 2B. The chart of FIG. 2B lists clutches and brakesin the left most column and the available zones to locate theclutch/brake in the top row. An “X” in the chart indicates that thepresent invention contemplates locating the clutch or brake in the zonelisted in the top row. For example, second brake 36 may be located inZones A, B, C, E, or F and first brake 34 may be located in zones A, B,E, or F.

Referring now to FIG. 3A, another embodiment of a transmission isgenerally indicated by reference number 200. The transmission 200 issimilar to transmission 10 and like components are indicated by likereference numbers. However, as shown in FIG. 3A, Zone A is defined bythe area or space bounded by: the first wall 102, planetary gear set 26,radially inward by a reference line “L” which is a longitudinal linethat is axially aligned with the input shaft 14, and radially outward bya reference line “M” which is a longitudinal line that extends adjacentan outer diameter or outer periphery of the planetary gear sets 20, 22,24 and 26. While reference line “M” is illustrated as a straight linethroughout the several views, it should be appreciated that referenceline “M” follows the outer periphery of the planetary gear sets 20, 22,24 and 26, and accordingly may be stepped or non-linear depending on thelocation of the outer periphery of each of the planetary gear sets 20,22, 24 and 26. Zone B is defined by the area bounded by: planetary gearset 26, the planetary gear set 20, radially outward by reference line“M”, and radially inward by reference line “L”. Zone C is defined by thearea bounded by: the planetary gear set 20, the planetary gear set 22,radially outward by reference line “M”, and radially inward by referenceline “L”. Zone D is defined by the area bounded by: the planetary gearset 22, the planetary gear set 24, radially outward by reference line“M”, and radially inward by reference line “L”. Zone E is defined by thearea bounded by: the planetary gear set 24, the second end wall 104,radially outward by reference line “M”, and radially inward by referenceline “L”. Zone F is defined by the area bounded by: the first wall 102,the second wall 104, radially inward by reference line “M” and radiallyoutward by the third wall 106.

In the gear arrangement 218 of transmission 200 shown in FIG. 3A, theplanetary gear set 26 is disposed closest to the first wall 102, theplanetary gear set 24 is disposed closest to the second wall 104, theplanetary gear set 20 is adjacent the planetary gear set 26, and theplanetary gear set 22 is disposed between the planetary gear sets 20 and24. The torque-transmitting mechanisms are intentionally located withinspecific Zones in order to provide advantages in overall transmissionsize, packaging efficiency, and reduced manufacturing complexity. In theparticular example shown in FIG. 3A, the first clutch 28 is disposed inZone D, the second clutch 30 is disposed in Zone D, the third clutch 32is disposed in Zone E, and the first brake 34 and the second brake 36are disposed in Zone A.

However, the present invention contemplates other embodiments where thetorque-transmitting mechanisms 28, 30, 32, 34 and 36 are disposed in theother Zones. The feasible locations of the torque-transmittingmechanisms 28, 30, 32, 34 and 36 within the Zones are illustrated in thechart shown in FIG. 3B. The chart of FIG. 3B lists clutches and brakesin the left most column and the available zones to locate theclutch/brake in the top row. An “X” in the chart indicates that thepresent invention contemplates locating the clutch or brake in the zonelisted in the top row. For example, second brake 36 may be located inZones A, B, C, E, or F and first brake 34 may be located in zones A, B,or F.

Referring now to FIG. 4A, another embodiment of a transmission isgenerally indicated by reference number 300. The transmission 300 issimilar to transmission 10 and like components are indicated by likereference numbers. However, as shown in FIG. 4A, Zone A is defined bythe area or space bounded by: the first wall 102, planetary gear set 26,radially inward by a reference line “L” which is a longitudinal linethat is axially aligned with the input shaft 14, and radially outward bya reference line “M” which is a longitudinal line that extends adjacentan outer diameter or outer periphery of the planetary gear sets 20, 22,24 and 26. While reference line “M” is illustrated as a straight linethroughout the several views, it should be appreciated that referenceline “M” follows the outer periphery of the planetary gear sets 20, 22,24 and 26, and accordingly may be stepped or non-linear depending on thelocation of the outer periphery of each of the planetary gear sets 20,22, 24 and 26. Zone B is defined by the area bounded by: planetary gearset 26, the planetary gear set 22, radially outward by reference line“M”, and radially inward by reference line “L”. Zone C is defined by thearea bounded by: the planetary gear set 22, the planetary gear set 20,radially outward by reference line “M”, and radially inward by referenceline “L”. Zone D is defined by the area bounded by: the planetary gearset 20, the planetary gear set 24, radially outward by reference line“M”, and radially inward by reference line “L”. Zone E is defined by thearea bounded by: the planetary gear set 24, the second end wall 104,radially outward by reference line “M”, and radially inward by referenceline “L”. Zone F is defined by the area bounded by: the first wall 102,the second wall 104, radially inward by reference line “M” and radiallyoutward by the third wall 106.

In the gear arrangement 318 of transmission 300 shown in FIG. 4A, theplanetary gear set 26 is disposed closest to the first wall 102, theplanetary gear set 24 is disposed closest to the second wall 104, theplanetary gear set 22 is adjacent the planetary gear set 26, and theplanetary gear set 20 is disposed between the planetary gear sets 22 and24. The torque-transmitting mechanisms are intentionally located withinspecific Zones in order to provide advantages in overall transmissionsize, packaging efficiency, and reduced manufacturing complexity. In theparticular example shown in FIG. 4A, the first clutch 28 is disposed inZone B, the second clutch 30 is disposed in Zone C, the third clutch 32is disposed in Zone E, and the first brake 34 and the second brake 36are disposed in Zone A.

However, the present invention contemplates other embodiments where thetorque-transmitting mechanisms 28, 30, 32, 34 and 36 are disposed in theother Zones. The feasible locations of the torque-transmittingmechanisms 28, 30, 32, 34 and 36 within the Zones are illustrated in thechart shown in FIG. 4B. The chart of FIG. 4B lists clutches and brakesin the left most column and the available zones to locate theclutch/brake in the top row. An “X” in the chart indicates that thepresent invention contemplates locating the clutch or brake in the zonelisted in the top row. For example, second brake 36 may be located inZones A, B, E, or F and first brake 34 may be located in zones A, B, orF.

Referring now to FIG. 5A, another embodiment of a transmission isgenerally indicated by reference number 400. The transmission 400 issimilar to transmission 10 and like components are indicated by likereference numbers. However, as shown in FIG. 5A, Zone A is defined bythe area or space bounded by: the first wall 102, planetary gear set 26,radially inward by a reference line “L” which is a longitudinal linethat is axially aligned with the input shaft 14, and radially outward bya reference line “M” which is a longitudinal line that extends adjacentan outer diameter or outer periphery of the planetary gear sets 20, 22,24 and 26. While reference line “M” is illustrated as a straight linethroughout the several views, it should be appreciated that referenceline “M” follows the outer periphery of the planetary gear sets 20, 22,24 and 26, and accordingly may be stepped or non-linear depending on thelocation of the outer periphery of each of the planetary gear sets 20,22, 24 and 26. Zone B is defined by the area bounded by: planetary gearset 26, the planetary gear set 24, radially outward by reference line“M”, and radially inward by reference line “L”. Zone C is defined by thearea bounded by: the planetary gear set 24, the planetary gear set 22,radially outward by reference line “M”, and radially inward by referenceline “L”. Zone D is defined by the area bounded by: the planetary gearset 22, the planetary gear set 20, radially outward by reference line“M”, and radially inward by reference line “L”. Zone E is defined by thearea bounded by: the planetary gear set 20, the second end wall 104,radially outward by reference line “M”, and radially inward by referenceline “L”. Zone F is defined by the area bounded by: the first wall 102,the second wall 104, radially inward by reference line “M” and radiallyoutward by the third wall 106.

In the gear arrangement 418 of transmission 400 shown in FIG. 5A, theplanetary gear set 26 is disposed closest to the first wall 102, theplanetary gear set 20 is disposed closest to the second wall 104, theplanetary gear set 24 is adjacent the planetary gear set 26, and theplanetary gear set 22 is disposed between the planetary gear sets 24 and20. The torque-transmitting mechanisms are intentionally located withinspecific Zones in order to provide advantages in overall transmissionsize, packaging efficiency, and reduced manufacturing complexity. In theparticular example shown in FIG. 5A, the first clutch 28 is disposed inZone B, the second clutch 30 is disposed in Zone D, the third clutch 32is disposed in Zone F, and the first brake 34 and the second brake 36are disposed in Zone A.

However, the present invention contemplates other embodiments where thetorque-transmitting mechanisms 28, 30, 32, 34 and 36 are disposed in theother Zones. The feasible locations of the torque-transmittingmechanisms 28, 30, 32, 34 and 36 within the Zones are illustrated in thechart shown in FIG. 5B. The chart of FIG. 5B lists clutches and brakesin the left most column and the available zones to locate theclutch/brake in the top row. An “X” in the chart indicates that thepresent invention contemplates locating the clutch or brake in the zonelisted in the top row. For example, second brake 36 may be located inZones A, B, C, or F and first brake 34 may be located in zones A, B, orF.

Referring now to FIG. 6, a front wheel drive powertrain 600incorporating a transaxle 602 is illustrated, in accordance with theembodiments of the present invention. Transaxle 602 includes thetransmission 10 having the gear arrangement 18 shown in FIGS. 1A and 1B.However, it should be appreciated that the transaxle 602 may incorporateany of the transmissions 10, 100, 200, 300, and 400 having any of thegear arrangements 18, 118, 218, 318, and 418 shown in FIGS. 1A through5B without departing from the scope of the present invention.Transmission 10 is mounted to an engine 604. Engine 604 provides adriving torque through input shaft 14 to transmission 10. Engine 604 isgenerally an internal combustion engine, however, the present inventioncontemplates other types of engines such as electric and hybrid engines.Further, transaxle 602 includes a transfer gear train 606, adifferential 608, and a pair of drive axles 610 and 612 that drive apair of road wheels 614 and 616, respectively.

Transfer gear train 606 includes a first transfer gear 618 and a secondtransfer gear 620. Output shaft or member 16 is coupled to the firsttransfer or spur gear 618. First transfer gear 618 may be a straightspur gear having straight gear teeth or a helical gear having helicalgear teeth. First transfer gear 618 meshes with the second transfer gear620. Second transfer gear 620 is rotatably fixed to an interconnectingshaft or rotatable member 622. Further, a pinion 624 is mounted to shaft622 and intermeshes with an input differential gear 626. Inputdifferential gear 626 transfers driving torque to the differential 608.Differential 608, as conventionally known, transfers the driving torquegenerated by engine 604 to the two drive axles 610 and 612. Drive axles610 and 612 are independently driven by differential 608 to supply thedriving torque to the vehicle road wheels 614 and 616.

Referring now to FIG. 7, another embodiment of a front wheel drivepowertrain 700 incorporating a transaxle 702 is illustrated, inaccordance with the embodiments of the present invention. Transaxle 702includes the transmission 10 having the gear arrangement 18 shown inFIGS. 1A and 1B. However, it should be appreciated that the transaxle702 may incorporate any of the transmissions 10, 100, 200, 300, and 400having any of the gear arrangements 18, 118, 218, 318, and 418 shown inFIGS. 1A through 5B without departing from the scope of the presentinvention. Transmission 10 is mounted to an engine 704. Engine 704provides a driving torque through input shaft 14 to transmission 10.Further, transaxle 702 includes a transfer chain 706, a driven sprocketor gear 708, a differential 710, a final drive planetary gear set 712and a pair of drive axles 714 and 716 that drive a pair of road wheels718 and 720, respectively.

Transfer chain 706 engages at a first end 722 a drive sprocket or gear724 and at a second end 726 the driven sprocket or gear 708. The drivesprocket 724 is coupled to output shaft or member 16. Driven sprocket708 is rotatably fixed to a drive shaft or rotatable member 728.Further, drive shaft 728 is coupled to the sun gear of the final driveplanetary gear set 712 to achieve the desired gear ratio. The finaldrive planetary gear set 712 transfers driving torque to thedifferential 710 though the carrier member of the final drive planetarygear set 712 to the housing of the differential 710. Differential 710,as conventionally known, transfers the driving torque generated byengine 704 to the two drive axles 714 and 716 through bevel gears ofdifferential 710. Drive axles 714 and are independently driven bydifferential 710 to supply the driving torque to the vehicle road wheels718 and 720.

The description of the invention is merely exemplary in nature andvariations that do not depart from the gist of the invention areintended to be within the scope of the invention. Such variations arenot to be regarded as a departure from the spirit and scope of theinvention.

1. A transaxle comprising: an input member; an output member; a housinghaving a first wall, a second wall, and a third wall extending betweenthe first and second walls; first, second, third and fourth planetarygear sets disposed within the housing, wherein the first planetary gearset is adjacent the first wall, the third planetary gear set is adjacentsecond wall, the fourth planetary gear set is adjacent the firstplanetary gear set and the second planetary gear set is between thefourth and third planetary gear sets, each planetary gear set having asun gear member, a ring gear member, and a planet carrier membersupporting a plurality of planet gears each configured to intermesh withboth the sun gear member and the ring gear member, and wherein the sungear member of the first planetary gear set is permanently coupled tothe sun gear member of the fourth planetary gear set, the ring gearmember of the first planetary gear set is permanently coupled to the sungear member of the second planetary gear set, the ring gear member ofthe second planetary gear set is permanently coupled to the sun gearmember of the third planetary gear set, the ring gear member of thethird planetary gear set is permanently coupled to the planet carriermember of the fourth planetary gear set, the input member is permanentlycoupled to the planet carrier member of the first planetary gear set,and the output member is permanently coupled to the planet carriermember of the third planetary gear set, wherein the housing has a firstarea defined radially inward from an outer periphery of the planetarygear sets and axially bounded by the first wall and the first planetarygear set, a second area defined radially inward from the outer peripheryof the planetary gear sets and axially bounded by the first and fourthplanetary gear sets, a third area defined radially inward from the outerperiphery of the planetary gear sets and axially bounded by the fourthand second planetary gear sets, a fourth area defined radially inwardfrom the outer periphery of the planetary gear sets and axially boundedby the second and third planetary gear sets, a fifth area definedradially inward from the outer periphery of the planetary gear sets andaxially bounded by the third planetary gear set and the second wall, anda sixth area defined radially inward from the third wall and radiallyoutward from the outer periphery of the planetary gear sets and axiallybounded by the first wall and the second wall, and a first clutchdisposed in at least one of the third, fourth, and sixth areas; a secondclutch disposed in at least one of the second, third, fourth, and fifthareas; a third clutch disposed in at least one of the fourth, fifth andsixth areas; a first brake disposed in at least one of the first,second, and sixth areas; and a second brake disposed in at least one ofthe first, second, third, fifth, and sixth areas, wherein the clutchesand the brakes are selectively engageable to establish at least eightforward speed ratios and at least one reverse speed ratio between theinput member and the output member, and a transfer gear train having afirst transfer gear intermeshed with a second transfer gear, wherein thefirst transfer gear is rotatably fixed to the output member and thesecond transfer gear is rotatably fixed to an intermediate shaft; adifferential gear set for driving a pair of road wheels; a pinion gearrotatably fixed to the intermediate shaft; and an input differentialgear in mesh with the pinion gear and configured to rotatably drive thedifferential gear set.
 2. The transaxle of claim 1 wherein the firstclutch is selectively engageable to interconnect the planet carriermember of the second planetary gear set with at least one of the planetcarrier member of the third planetary gear set and the output member,the second clutch is selectively engageable to interconnect at least oneof the sun gear member of the second planetary gear set and the ringgear member of the first planetary gear set with at least one of the sungear member of the third planetary gear set and the ring gear member ofthe second planetary gear set, the third clutch is selectivelyengageable to interconnect at least one of the sun gear member of thethird planetary gear set and the ring gear member of the secondplanetary gear set with at least one of the planet carrier member of thefirst planetary gear set and the input member, the first brake isselectively engageable to interconnect at least one of the sun gearmember of the first planetary gear set and the sun gear member of thefourth planetary gear set with the housing, and the second brake isselectively engageable to interconnect the ring gear member of thefourth planetary gear set with the housing.
 3. The transaxle of claim 2wherein the first clutch is disposed in the third area, the secondclutch is disposed in the fourth area, the third clutch is disposed inthe fifth area, the first brake is disposed in the first area, and thesecond brake is disposed in the third area.
 4. A transaxle comprising:an input member; an output member; a housing having a first wall, asecond wall, and a third wall extending between the first and secondwalls; first, second, third and fourth planetary gear sets disposedwithin the housing, wherein the first planetary gear set is adjacent thefirst wall, the third planetary gear set is adjacent second wall, thefourth planetary gear set is adjacent the first planetary gear set andthe second planetary gear set is between the fourth and third planetarygear sets, each planetary gear set having a sun gear member, a ring gearmember, and a planet carrier member supporting a plurality of planetgears each configured to intermesh with both the sun gear member and thering gear member, and wherein the sun gear member of the first planetarygear set is permanently coupled to the sun gear member of the fourthplanetary gear set, the ring gear member of the first planetary gear setis permanently coupled to the sun gear member of the second planetarygear set, the ring gear member of the second planetary gear set ispermanently coupled to the sun gear member of the third planetary gearset, the ring gear member of the third planetary gear set is permanentlycoupled to the planet carrier member of the fourth planetary gear set,the input member is permanently coupled to the planet carrier member ofthe first planetary gear set, and the output member is permanentlycoupled to the planet carrier member of the third planetary gear set,and wherein the housing has a first area defined radially inward from anouter periphery of the planetary gear sets and axially bounded by thefirst wall and the first planetary gear set, a second area definedradially inward from the outer periphery of the planetary gear sets andaxially bounded by the first and fourth planetary gear sets, a thirdarea defined radially inward from the outer periphery of the planetarygear sets and axially bounded by the fourth and second planetary gearsets, a fourth area defined radially inward from the outer periphery ofthe planetary gear sets and axially bounded by the second and thirdplanetary gear sets, a fifth area defined radially inward from the outerperiphery of the planetary gear sets and axially bounded by the thirdplanetary gear set and the second wall, and a sixth area definedradially inward from the third wall and radially outward from the outerperiphery of the planetary gear sets and axially bounded by the firstwall and the second wall, a first clutch disposed in at least one of thethird, fourth, and sixth areas; a second clutch disposed in at least oneof the second, third, fourth, and fifth areas; a third clutch disposedin at least one of the fourth, fifth and sixth areas; a first brakedisposed in at least one of the first, second, and sixth areas; a secondbrake disposed in at least one of the first, second, third, fifth, andsixth areas, and wherein the clutches and the brakes are selectivelyengageable to establish at least eight forward speed ratios and at leastone reverse speed ratio between the input member and the output member,a power transfer assembly having a first transfer gear and a secondtransfer gear, wherein the first transfer gear is rotatably fixed to theoutput member and the second transfer gear is rotatably fixed to a driveshaft; a power transfer member rotatably coupling the first and secondtransfer gears for transferring rotational energy from the firsttransfer gear to the second transfer gear; a final drive planetary gearset coupled to the drive shaft for receiving a driving torque from thesecond transfer gear; and a differential gear set coupled to the finaldrive planetary gear set and to a pair of road wheels for receiving afinal drive rotational torque and transferring the final drive torque tothe pair of road wheels.
 5. The transaxle of claim 4, wherein the powertransfer member is a chain or a belt.
 6. The transaxle of claim 4wherein the first clutch is selectively engageable to interconnect theplanet carrier member of the second planetary gear set with at least oneof the planet carrier member of the third planetary gear set and theoutput member, the second clutch is selectively engageable tointerconnect at least one of the sun gear member of the second planetarygear set and the ring gear member of the first planetary gear set withat least one of the sun gear member of the third planetary gear set andthe ring gear member of the second planetary gear set, the third clutchis selectively engageable to interconnect at least one of the sun gearmember of the third planetary gear set and the ring gear member of thesecond planetary gear set with at least one of the planet carrier memberof the first planetary gear set and the input member, the first brake isselectively engageable to interconnect at least one of the sun gearmember of the first planetary gear set and the sun gear member of thefourth planetary gear set with the housing, and the second brake isselectively engageable to interconnect the ring gear member of thefourth planetary gear set with the housing.
 7. The transaxle of claim 6wherein the first clutch is disposed in the third area, the secondclutch is disposed in the fourth area, the third clutch is disposed inthe fifth area, the first brake is disposed in the first area, and thesecond brake is disposed in the third area.
 8. A transaxle comprising:an input member; an output member; a housing having a first wall, asecond wall, and a third wall extending between the first and secondwalls; first, second, third and fourth planetary gear sets disposedwithin the housing, wherein the first planetary gear set is adjacent thefirst wall, the third planetary gear set is adjacent second wall, thefourth planetary gear set is adjacent the first planetary gear set andthe second planetary gear set is between the fourth and third planetarygear sets, each planetary gear set having a sun gear member, a ring gearmember, and a planet carrier member supporting a plurality of planetgears each configured to intermesh with both the sun gear member and thering gear member, and wherein the sun gear member of the first planetarygear set is permanently coupled to the sun gear member of the fourthplanetary gear set, the ring gear member of the first planetary gear setis permanently coupled to the sun gear member of the second planetarygear set, the ring gear member of the second planetary gear set ispermanently coupled to the sun gear member of the third planetary gearset, the ring gear member of the third planetary gear set is permanentlycoupled to the planet carrier member of the fourth planetary gear set,the input member is permanently coupled to the planet carrier member ofthe first planetary gear set, and the output member is permanentlycoupled to the planet carrier member of the third planetary gear set,and wherein the housing has a first area defined radially inward from anouter periphery of the planetary gear sets and axially bounded by thefirst wall and the first planetary gear set, a second area definedradially inward from the outer periphery of the planetary gear sets andaxially bounded by the first and fourth planetary gear sets, a thirdarea defined radially inward from the outer periphery of the planetarygear sets and axially bounded by the fourth and second planetary gearsets, a fourth area defined radially inward from the outer periphery ofthe planetary gear sets and axially bounded by the second and thirdplanetary gear sets, a fifth area defined radially inward from the outerperiphery of the planetary gear sets and axially bounded by the thirdplanetary gear set and the second wall, and a sixth area definedradially inward from the third wall and radially outward from the outerperiphery of the planetary gear sets and axially bounded by the firstwall and the second wall, a first clutch disposed in at least one of thethird, fourth, and sixth areas; a second clutch disposed in at least oneof the first, third, fourth, and fifth areas; a third clutch disposed inat least one of the first, fourth, fifth and sixth areas; a first brakedisposed in at least one of the first, second, fifth, and sixth areas; asecond brake disposed in at least one of the first, second, third,fifth, and sixth areas, and wherein the clutches and the brakes areselectively engageable to establish at least eight forward speed ratiosand at least one reverse speed ratio between the input member and theoutput member, a transfer gear train having a first transfer gearintermeshed with a second transfer gear, wherein the first transfer gearis rotatably fixed to the output member and the second transfer gear isrotatably fixed to an intermediate shaft; a differential gear set fordriving a pair of road wheels; a pinion gear rotatably fixed to theintermediate shaft; and an input differential gear in mesh with thepinion gear and configured to rotatably drive the differential gear set.9. The transaxle of claim 8 wherein the first clutch is selectivelyengageable to interconnect the planet carrier member of the secondplanetary gear set with at least one of the planet carrier member of thethird planetary gear set and the output member, the second clutch isselectively engageable to interconnect at least one of the sun gearmember of the second planetary gear set and the ring gear member of thefirst planetary gear set with at least one of the sun gear member of thethird planetary gear set and the ring gear member of the secondplanetary gear set, the third clutch is selectively engageable tointerconnect at least one of the sun gear member of the third planetarygear set and the ring gear member of the second planetary gear set withat least one of the planet carrier member of the first planetary gearset and the input member, the first brake is selectively engageable tointerconnect at least one of the sun gear member of the first planetarygear set and the sun gear member of the fourth planetary gear set withthe housing, and the second brake is selectively engageable tointerconnect the ring gear member of the fourth planetary gear set withthe housing.
 10. The transaxle of claim 9 wherein the first clutch isdisposed in the third area, the second clutch is disposed in the fourtharea, the third clutch is disposed in the fifth area, the first brake isdisposed in the second area, and the second brake is disposed in thesecond area.
 11. A transaxle comprising: an input member; an outputmember; a housing having a first wall, a second wall, and a third wallextending between the first and second walls; first, second, third andfourth planetary gear sets disposed within the housing, wherein thefirst planetary gear set is adjacent the first wall, the third planetarygear set is adjacent second wall, the fourth planetary gear set isadjacent the first planetary gear set and the second planetary gear setis between the fourth and third planetary gear sets, each planetary gearset having a sun gear member, a ring gear member, and a planet carriermember supporting a plurality of planet gears each configured tointermesh with both the sun gear member and the ring gear member, andwherein the sun gear member of the first planetary gear set ispermanently coupled to the sun gear member of the fourth planetary gearset, the ring gear member of the first planetary gear set is permanentlycoupled to the sun gear member of the second planetary gear set, thering gear member of the second planetary gear set is permanently coupledto the sun gear member of the third planetary gear set, the ring gearmember of the third planetary gear set is permanently coupled to theplanet carrier member of the fourth planetary gear set, the input memberis permanently coupled to the planet carrier member of the firstplanetary gear set, and the output member is permanently coupled to theplanet carrier member of the third planetary gear set, and wherein thehousing has a first area defined radially inward from an outer peripheryof the planetary gear sets and axially bounded by the first wall and thefirst planetary gear set, a second area defined radially inward from theouter periphery of the planetary gear sets and axially bounded by thefirst and fourth planetary gear sets, a third area defined radiallyinward from the outer periphery of the planetary gear sets and axiallybounded by the fourth and second planetary gear sets, a fourth areadefined radially inward from the outer periphery of the planetary gearsets and axially bounded by the second and third planetary gear sets, afifth area defined radially inward from the outer periphery of theplanetary gear sets and axially bounded by the third planetary gear setand the second wall, and a sixth area defined radially inward from thethird wall and radially outward from the outer periphery of theplanetary gear sets and axially bounded by the first wall and the secondwall, a first clutch disposed in at least one of the third, fourth, andsixth areas; a second clutch disposed in at least one of the first,third, fourth, and fifth areas; a third clutch disposed in at least oneof the first, fourth, fifth and sixth areas; a first brake disposed inat least one of the first, second, fifth, and sixth areas; a secondbrake disposed in at least one of the first, second, third, fifth, andsixth areas, and wherein the clutches and the brakes are selectivelyengageable to establish at least eight forward speed ratios and at leastone reverse speed ratio between the input member and the output member,a power transfer assembly having a first transfer gear and a secondtransfer gear, wherein the first transfer gear is rotatably fixed to theoutput member and the second transfer gear is rotatably fixed to a driveshaft; a power transfer member rotatably coupling the first and secondtransfer gears for transferring rotational energy from the firsttransfer gear to the second transfer gear; a final drive planetary gearset coupled to the drive shaft for receiving a driving torque from thesecond transfer gear; and a differential gear set coupled to the finaldrive planetary gear set and to a pair of road wheels for receiving afinal drive rotational torque and transferring the final drive torque tothe pair of road wheels.
 12. The transaxle of claim 11, wherein thepower transfer member is a chain or a belt.
 13. The transaxle of claim11 wherein the first clutch is selectively engageable to interconnectthe planet carrier member of the second planetary gear set with at leastone of the planet carrier member of the third planetary gear set and theoutput member, the second clutch is selectively engageable tointerconnect at least one of the sun gear member of the second planetarygear set and the ring gear member of the first planetary gear set withat least one of the sun gear member of the third planetary gear set andthe ring gear member of the second planetary gear set, the third clutchis selectively engageable to interconnect at least one of the sun gearmember of the third planetary gear set and the ring gear member of thesecond planetary gear set with at least one of the planet carrier memberof the first planetary gear set and the input member, the first brake isselectively engageable to interconnect at least one of the sun gearmember of the first planetary gear set and the sun gear member of thefourth planetary gear set with the housing, and the second brake isselectively engageable to interconnect the ring gear member of thefourth planetary gear set with the housing.
 14. The transaxle of claim13 wherein the first clutch is disposed in the third area, the secondclutch is disposed in the fourth area, the third clutch is disposed inthe fifth area, the first brake is disposed in the second area, and thesecond brake is disposed in the second area.
 15. A transaxle comprising:an input member; an output member; a housing having a first wall, asecond wall, and a third wall extending between the first and secondwalls; first, second, third and fourth planetary gear sets disposedwithin the housing, wherein the fourth planetary gear set is adjacentthe first wall, the third planetary gear set is adjacent second wall,the first planetary gear set is adjacent the fourth planetary gear setand the second planetary gear set is between the first and thirdplanetary gear sets, each planetary gear set having a sun gear member, aring gear member, and a planet carrier member supporting a plurality ofplanet gears each configured to intermesh with both the sun gear memberand the ring gear member, and wherein the sun gear member of the firstplanetary gear set is permanently coupled to the sun gear member of thefourth planetary gear set, the ring gear member of the first planetarygear set is permanently coupled to the sun gear member of the secondplanetary gear set, the ring gear member of the second planetary gearset is permanently coupled to the sun gear member of the third planetarygear set, the ring gear member of the third planetary gear set ispermanently coupled to the planet carrier member of the fourth planetarygear set, the input member is permanently coupled to the planet carriermember of the first planetary gear set, and the output member ispermanently coupled to the planet carrier member of the third planetarygear set, and wherein the housing has a first area defined radiallyinward from an outer periphery of the planetary gear sets and axiallybounded by the first wall and the fourth planetary gear set, a secondarea defined radially inward from the outer periphery of the planetarygear sets and axially bounded by the fourth and first planetary gearsets, a third area defined radially inward from the outer periphery ofthe planetary gear sets and axially bounded by the first and secondplanetary gear sets, a fourth area defined radially inward from theouter periphery of the planetary gear sets and axially bounded by thesecond and third planetary gear sets, a fifth area defined radiallyinward from the outer periphery of the planetary gear sets and axiallybounded by the third planetary gear set and the second wall, and a sixtharea defined radially inward from the third wall and radially outwardfrom the outer periphery of the planetary gear sets and axially boundedby the first wall and the second wall, a first clutch disposed in atleast one of the third, fourth, and sixth areas; a second clutchdisposed in at least one of the third, fourth, and fifth areas; a thirdclutch disposed in at least one of the third, fourth, fifth and sixthareas; a first brake disposed in at least one of the first, second, andsixth areas; a second brake disposed in at least one of the first,second, third, fifth, and sixth areas, and wherein the clutches and thebrakes are selectively engageable to establish at least eight forwardspeed ratios and at least one reverse speed ratio between the inputmember and the output member, a transfer gear train having a firsttransfer gear intermeshed with a second transfer gear, wherein the firsttransfer gear is rotatably fixed to the output member and the secondtransfer gear is rotatably fixed to an intermediate shaft; adifferential gear set for driving a pair of road wheels; a pinion gearrotatably fixed to the intermediate shaft; and an input differentialgear in mesh with the pinion gear and configured to rotatably drive thedifferential gear set.
 16. The transaxle of claim 15 wherein the firstclutch is selectively engageable to interconnect the planet carriermember of the second planetary gear set with at least one of the planetcarrier member of the third planetary gear set and the output member,the second clutch is selectively engageable to interconnect at least oneof the sun gear member of the second planetary gear set and the ringgear member of the first planetary gear set with at least one of the sungear member of the third planetary gear set and the ring gear member ofthe second planetary gear set, the third clutch is selectivelyengageable to interconnect at least one of the sun gear member of thethird planetary gear set and the ring gear member of the secondplanetary gear set with at least one of the planet carrier member of thefirst planetary gear set and the input member, the first brake isselectively engageable to interconnect at least one of the sun gearmember of the first planetary gear set and the sun gear member of thefourth planetary gear set with the housing, and the second brake isselectively engageable to interconnect the ring gear member of thefourth planetary gear set with the housing.
 17. The transaxle of claim16 wherein the first clutch is disposed in the fourth area, the secondclutch is disposed in the fourth area, the third clutch is disposed inthe fifth area, the first brake is disposed in the first area, and thesecond brake is disposed in the first area.
 18. A transaxle comprising:an input member; an output member; a housing having a first wall, asecond wall, and a third wall extending between the first and secondwalls; first, second, third and fourth planetary gear sets disposedwithin the housing, wherein the fourth planetary gear set is adjacentthe first wall, the third planetary gear set is adjacent second wall,the first planetary gear set is adjacent the fourth planetary gear setand the second planetary gear set is between the first and thirdplanetary gear sets, each planetary gear set having a sun gear member, aring gear member, and a planet carrier member supporting a plurality ofplanet gears each configured to intermesh with both the sun gear memberand the ring gear member, and wherein the sun gear member of the firstplanetary gear set is permanently coupled to the sun gear member of thefourth planetary gear set, the ring gear member of the first planetarygear set is permanently coupled to the sun gear member of the secondplanetary gear set, the ring gear member of the second planetary gearset is permanently coupled to the sun gear member of the third planetarygear set, the ring gear member of the third planetary gear set ispermanently coupled to the planet carrier member of the fourth planetarygear set, the input member is permanently coupled to the planet carriermember of the first planetary gear set, and the output member ispermanently coupled to the planet carrier member of the third planetarygear set, and wherein the housing has a first area defined radiallyinward from an outer periphery of the planetary gear sets and axiallybounded by the first wall and the fourth planetary gear set, a secondarea defined radially inward from the outer periphery of the planetarygear sets and axially bounded by the fourth and first planetary gearsets, a third area defined radially inward from the outer periphery ofthe planetary gear sets and axially bounded by the first and secondplanetary gear sets, a fourth area defined radially inward from theouter periphery of the planetary gear sets and axially bounded by thesecond and third planetary gear sets, a fifth area defined radiallyinward from the outer periphery of the planetary gear sets and axiallybounded by the third planetary gear set and the second wall, and a sixtharea defined radially inward from the third wall and radially outwardfrom the outer periphery of the planetary gear sets and axially boundedby the first wall and the second wall, a first clutch disposed in atleast one of the third, fourth, and sixth areas; a second clutchdisposed in at least one of the third, fourth, and fifth areas; a thirdclutch disposed in at least one of the third, fourth, fifth and sixthareas; a first brake disposed in at least one of the first, second, andsixth areas; a second brake disposed in at least one of the first,second, third, fifth, and sixth areas, and wherein the clutches and thebrakes are selectively engageable to establish at least eight forwardspeed ratios and at least one reverse speed ratio between the inputmember and the output member, a power transfer assembly having a firsttransfer gear and a second transfer gear, wherein the first transfergear is rotatably fixed to the output member and the second transfergear is rotatably fixed to a drive shaft; a power transfer memberrotatably coupling the first and second transfer gears for transferringrotational energy from the first transfer gear to the second transfergear; a final drive planetary gear set coupled to the drive shaft forreceiving a driving torque from the second transfer gear; and adifferential gear set coupled to the final drive planetary gear set andto a pair of road wheels for receiving a final drive rotational torqueand transferring the final drive torque to the pair of road wheels. 19.The transaxle of claim 18, wherein the power transfer member is a chainor a belt.
 20. The transaxle of claim 18 wherein the first clutch isselectively engageable to interconnect the planet carrier member of thesecond planetary gear set with at least one of the planet carrier memberof the third planetary gear set and the output member, the second clutchis selectively engageable to interconnect at least one of the sun gearmember of the second planetary gear set and the ring gear member of thefirst planetary gear set with at least one of the sun gear member of thethird planetary gear set and the ring gear member of the secondplanetary gear set, the third clutch is selectively engageable tointerconnect at least one of the sun gear member of the third planetarygear set and the ring gear member of the second planetary gear set withat least one of the planet carrier member of the first planetary gearset and the input member, the first brake is selectively engageable tointerconnect at least one of the sun gear member of the first planetarygear set and the sun gear member of the fourth planetary gear set withthe housing, and the second brake is selectively engageable tointerconnect the ring gear member of the fourth planetary gear set withthe housing.
 21. The transaxle of claim 20 wherein the first clutch isdisposed in the fourth area, the second clutch is disposed in the fourtharea, the third clutch is disposed in the fifth area, the first brake isdisposed in the first area, and the second brake is disposed in thefirst area.
 22. A transaxle comprising: an input member; an outputmember; a housing having a first wall, a second wall, and a third wallextending between the first and second walls; first, second, third andfourth planetary gear sets disposed within the housing, wherein thefourth planetary gear set is adjacent the first wall, the thirdplanetary gear set is adjacent second wall, the second planetary gearset is adjacent the fourth planetary gear set and the first planetarygear set is between the second and third planetary gear sets, eachplanetary gear set having a sun gear member, a ring gear member, and aplanet carrier member supporting a plurality of planet gears eachconfigured to intermesh with both the sun gear member and the ring gearmember, and wherein the sun gear member of the first planetary gear setis permanently coupled to the sun gear member of the fourth planetarygear set, the ring gear member of the first planetary gear set ispermanently coupled to the sun gear member of the second planetary gearset, the ring gear member of the second planetary gear set ispermanently coupled to the sun gear member of the third planetary gearset, the ring gear member of the third planetary gear set is permanentlycoupled to the planet carrier member of the fourth planetary gear set,the input member is permanently coupled to the planet carrier member ofthe first planetary gear set, and the output member is permanentlycoupled to the planet carrier member of the third planetary gear set,and wherein the housing has a first area defined radially inward from anouter periphery of the planetary gear sets and axially bounded by thefirst wall and the fourth planetary gear set, a second area definedradially inward from the outer periphery of the planetary gear sets andaxially bounded by the fourth and second planetary gear sets, a thirdarea defined radially inward from the outer periphery of the planetarygear sets and axially bounded by the first and second planetary gearsets, a fourth area defined radially inward from the outer periphery ofthe planetary gear sets and axially bounded by the first and thirdplanetary gear sets, a fifth area defined radially inward from the outerperiphery of the planetary gear sets and axially bounded by the thirdplanetary gear set and the second wall, and a sixth area definedradially inward from the third wall and radially outward from the outerperiphery of the planetary gear sets and axially bounded by the firstwall and the second wall, a first clutch disposed in at least one of thesecond, fourth, and sixth areas; a second clutch disposed in at leastone of the second, third, and sixth areas; a third clutch disposed in atleast one of the fourth, fifth and sixth areas; a first brake disposedin at least one of the first, second, and sixth areas; a second brakedisposed in at least one of the first, second, fifth, and sixth areas,and wherein the clutches and the brakes are selectively engageable toestablish at least eight forward speed ratios and at least one reversespeed ratio between the input member and the output member, a transfergear train having a first transfer gear intermeshed with a secondtransfer gear, wherein the first transfer gear is rotatably fixed to theoutput member and the second transfer gear is rotatably fixed to anintermediate shaft; a differential gear set for driving a pair of roadwheels; a pinion gear rotatably fixed to the intermediate shaft; and aninput differential gear in mesh with the pinion gear and configured torotatably drive the differential gear set.
 23. The transaxle of claim 22wherein the first clutch is selectively engageable to interconnect theplanet carrier member of the second planetary gear set with at least oneof the planet carrier member of the third planetary gear set and theoutput member, the second clutch is selectively engageable tointerconnect at least one of the sun gear member of the second planetarygear set and the ring gear member of the first planetary gear set withat least one of the sun gear member of the third planetary gear set andthe ring gear member of the second planetary gear set, the third clutchis selectively engageable to interconnect at least one of the sun gearmember of the third planetary gear set and the ring gear member of thesecond planetary gear set with at least one of the planet carrier memberof the first planetary gear set and the input member, the first brake isselectively engageable to interconnect at least one of the sun gearmember of the first planetary gear set and the sun gear member of thefourth planetary gear set with the housing, and the second brake isselectively engageable to interconnect the ring gear member of thefourth planetary gear set with the housing.
 24. The transaxle of claim23 wherein the first clutch is disposed in the second area, the secondclutch is disposed in the third area, the third clutch is disposed inthe fifth area, the first brake is disposed in the first area, and thesecond brake is disposed in the first area.
 25. A transaxle comprising:an input member; an output member; a housing having a first wall, asecond wall, and a third wall extending between the first and secondwalls; first, second, third and fourth planetary gear sets disposedwithin the housing, wherein the fourth planetary gear set is adjacentthe first wall, the third planetary gear set is adjacent second wall,the second planetary gear set is adjacent the fourth planetary gear setand the first planetary gear set is between the second and thirdplanetary gear sets, each planetary gear set having a sun gear member, aring gear member, and a planet carrier member supporting a plurality ofplanet gears each configured to intermesh with both the sun gear memberand the ring gear member, and wherein the sun gear member of the firstplanetary gear set is permanently coupled to the sun gear member of thefourth planetary gear set, the ring gear member of the first planetarygear set is permanently coupled to the sun gear member of the secondplanetary gear set, the ring gear member of the second planetary gearset is permanently coupled to the sun gear member of the third planetarygear set, the ring gear member of the third planetary gear set ispermanently coupled to the planet carrier member of the fourth planetarygear set, the input member is permanently coupled to the planet carriermember of the first planetary gear set, and the output member ispermanently coupled to the planet carrier member of the third planetarygear set, and wherein the housing has a first area defined radiallyinward from an outer periphery of the planetary gear sets and axiallybounded by the first wall and the fourth planetary gear set, a secondarea defined radially inward from the outer periphery of the planetarygear sets and axially bounded by the fourth and second planetary gearsets, a third area defined radially inward from the outer periphery ofthe planetary gear sets and axially bounded by the first and secondplanetary gear sets, a fourth area defined radially inward from theouter periphery of the planetary gear sets and axially bounded by thefirst and third planetary gear sets, a fifth area defined radiallyinward from the outer periphery of the planetary gear sets and axiallybounded by the third planetary gear set and the second wall, and a sixtharea defined radially inward from the third wall and radially outwardfrom the outer periphery of the planetary gear sets and axially boundedby the first wall and the second wall, a first clutch disposed in atleast one of the second, fourth, and sixth areas; a second clutchdisposed in at least one of the second, third, and sixth areas; a thirdclutch disposed in at least one of the fourth, fifth and sixth areas; afirst brake disposed in at least one of the first, second, and sixthareas; a second brake disposed in at least one of the first, second,fifth, and sixth areas, and wherein the clutches and the brakes areselectively engageable to establish at least eight forward speed ratiosand at least one reverse speed ratio between the input member and theoutput member, a power transfer assembly having a first transfer gearand a second transfer gear, wherein the first transfer gear is rotatablyfixed to the output member and the second transfer gear is rotatablyfixed to a drive shaft; a power transfer member rotatably coupling thefirst and second transfer gears for transferring rotational energy fromthe first transfer gear to the second transfer gear; a final driveplanetary gear set coupled to the drive shaft for receiving a drivingtorque from the second transfer gear; and a differential gear setcoupled to the final drive planetary gear set and to a pair of roadwheels for receiving a final drive rotational torque and transferringthe final drive torque to the pair of road wheels.
 26. The transaxle ofclaim 25, wherein the power transfer member is a chain or a belt. 27.The transaxle of claim 25 wherein the first clutch is selectivelyengageable to interconnect the planet carrier member of the secondplanetary gear set with at least one of the planet carrier member of thethird planetary gear set and the output member, the second clutch isselectively engageable to interconnect at least one of the sun gearmember of the second planetary gear set and the ring gear member of thefirst planetary gear set with at least one of the sun gear member of thethird planetary gear set and the ring gear member of the secondplanetary gear set, the third clutch is selectively engageable tointerconnect at least one of the sun gear member of the third planetarygear set and the ring gear member of the second planetary gear set withat least one of the planet carrier member of the first planetary gearset and the input member, the first brake is selectively engageable tointerconnect at least one of the sun gear member of the first planetarygear set and the sun gear member of the fourth planetary gear set withthe housing, and the second brake is selectively engageable tointerconnect the ring gear member of the fourth planetary gear set withthe housing.
 28. The transaxle of claim 27 wherein the first clutch isdisposed in the second area, the second clutch is disposed in the thirdarea, the third clutch is disposed in the fifth area, the first brake isdisposed in the first area, and the second brake is disposed in thefirst area.
 29. A transaxle comprising: an input member; an outputmember; a housing having a first wall, a second wall, and a third wallextending between the first and second walls; first, second, third andfourth planetary gear sets disposed within the housing, wherein thefourth planetary gear set is adjacent the first wall, the firstplanetary gear set is adjacent second wall, the third planetary gear setis adjacent the fourth planetary gear set and the second planetary gearset is between the third and first planetary gear sets, each planetarygear set having a sun gear member, a ring gear member, and a planetcarrier member supporting a plurality of planet gears each configured tointermesh with both the sun gear member and the ring gear member, andwherein the sun gear member of the first planetary gear set ispermanently coupled to the sun gear member of the fourth planetary gearset, the ring gear member of the first planetary gear set is permanentlycoupled to the sun gear member of the second planetary gear set, thering gear member of the second planetary gear set is permanently coupledto the sun gear member of the third planetary gear set, the ring gearmember of the third planetary gear set is permanently coupled to theplanet carrier member of the fourth planetary gear set, the input memberis permanently coupled to the planet carrier member of the firstplanetary gear set, and the output member is permanently coupled to theplanet carrier member of the third planetary gear set, and wherein thehousing has a first area defined radially inward from an outer peripheryof the planetary gear sets and axially bounded by the first wall and thefourth planetary gear set, a second area defined radially inward fromthe outer periphery of the planetary gear sets and axially bounded bythe fourth and third planetary gear sets, a third area defined radiallyinward from the outer periphery of the planetary gear sets and axiallybounded by the third and second planetary gear sets, a fourth areadefined radially inward from the outer periphery of the planetary gearsets and axially bounded by the second and first planetary gear sets, afifth area defined radially inward from the outer periphery of theplanetary gear sets and axially bounded by the first planetary gear setand the second wall, and a sixth area defined radially inward from thethird wall and radially outward from the outer periphery of theplanetary gear sets and axially bounded by the first wall and the secondwall, a first clutch disposed in at least one of the second, third, andsixth areas; a second clutch disposed in at least one of the third,fourth, and sixth areas; a third clutch disposed in at least one of thethird, fourth, fifth and sixth areas; a first brake disposed in at leastone of the first, second, and sixth areas; a second brake disposed in atleast one of the first, second, third, and sixth areas, and wherein theclutches and the brakes are selectively engageable to establish at leasteight forward speed ratios and at least one reverse speed ratio betweenthe input member and the output member, a transfer gear train having afirst transfer gear intermeshed with a second transfer gear, wherein thefirst transfer gear is rotatably fixed to the output member and thesecond transfer gear is rotatably fixed to an intermediate shaft; adifferential gear set for driving a pair of road wheels; a pinion gearrotatably fixed to the intermediate shaft; and an input differentialgear in mesh with the pinion gear and configured to rotatably drive thedifferential gear set.
 30. The transaxle of claim 29 wherein the firstclutch is selectively engageable to interconnect the planet carriermember of the second planetary gear set with at least one of the planetcarrier member of the third planetary gear set and the output member,the second clutch is selectively engageable to interconnect at least oneof the sun gear member of the second planetary gear set and the ringgear member of the first planetary gear set with at least one of the sungear member of the third planetary gear set and the ring gear member ofthe second planetary gear set, the third clutch is selectivelyengageable to interconnect at least one of the sun gear member of thethird planetary gear set and the ring gear member of the secondplanetary gear set with at least one of the planet carrier member of thefirst planetary gear set and the input member, the first brake isselectively engageable to interconnect at least one of the sun gearmember of the first planetary gear set and the sun gear member of thefourth planetary gear set with the housing, and the second brake isselectively engageable to interconnect the ring gear member of thefourth planetary gear set with the housing.
 31. The transaxle of claim30 wherein the first clutch is disposed in the second area, the secondclutch is disposed in the fourth area, the third clutch is disposed inthe sixth area, the first brake is disposed in the first area, and thesecond brake is disposed in the first area.
 32. A transaxle comprising:an input member; an output member; a housing having a first wall, asecond wall, and a third wall extending between the first and secondwalls; first, second, third and fourth planetary gear sets disposedwithin the housing, wherein the fourth planetary gear set is adjacentthe first wall, the first planetary gear set is adjacent second wall,the third planetary gear set is adjacent the fourth planetary gear setand the second planetary gear set is between the third and firstplanetary gear sets, each planetary gear set having a sun gear member, aring gear member, and a planet carrier member supporting a plurality ofplanet gears each configured to intermesh with both the sun gear memberand the ring gear member, and wherein the sun gear member of the firstplanetary gear set is permanently coupled to the sun gear member of thefourth planetary gear set, the ring gear member of the first planetarygear set is permanently coupled to the sun gear member of the secondplanetary gear set, the ring gear member of the second planetary gearset is permanently coupled to the sun gear member of the third planetarygear set, the ring gear member of the third planetary gear set ispermanently coupled to the planet carrier member of the fourth planetarygear set, the input member is permanently coupled to the planet carriermember of the first planetary gear set, and the output member ispermanently coupled to the planet carrier member of the third planetarygear set, and wherein the housing has a first area defined radiallyinward from an outer periphery of the planetary gear sets and axiallybounded by the first wall and the fourth planetary gear set, a secondarea defined radially inward from the outer periphery of the planetarygear sets and axially bounded by the fourth and third planetary gearsets, a third area defined radially inward from the outer periphery ofthe planetary gear sets and axially bounded by the third and secondplanetary gear sets, a fourth area defined radially inward from theouter periphery of the planetary gear sets and axially bounded by thesecond and first planetary gear sets, a fifth area defined radiallyinward from the outer periphery of the planetary gear sets and axiallybounded by the first planetary gear set and the second wall, and a sixtharea defined radially inward from the third wall and radially outwardfrom the outer periphery of the planetary gear sets and axially boundedby the first wall and the second wall, a first clutch disposed in atleast one of the second, third, and sixth areas; a second clutchdisposed in at least one of the third, fourth, and sixth areas; a thirdclutch disposed in at least one of the third, fourth, fifth and sixthareas; a first brake disposed in at least one of the first, second, andsixth areas; a second brake disposed in at least one of the first,second, third, and sixth areas, and wherein the clutches and the brakesare selectively engageable to establish at least eight forward speedratios and at least one reverse speed ratio between the input member andthe output member, a power transfer assembly having a first transfergear and a second transfer gear, wherein the first transfer gear isrotatably fixed to the output member and the second transfer gear isrotatably fixed to a drive shaft; a power transfer member rotatablycoupling the first and second transfer gears for transferring rotationalenergy from the first transfer gear to the second transfer gear; a finaldrive planetary gear set coupled to the drive shaft for receiving adriving torque from the second transfer gear; and a differential gearset coupled to the final drive planetary gear set and to a pair of roadwheels for receiving a final drive rotational torque and transferringthe final drive torque to the pair of road wheels.
 33. The transaxle ofclaim 32, wherein the power transfer member is a chain or a belt. 34.The transaxle of claim 32 wherein the first clutch is selectivelyengageable to interconnect the planet carrier member of the secondplanetary gear set with at least one of the planet carrier member of thethird planetary gear set and the output member, the second clutch isselectively engageable to interconnect at least one of the sun gearmember of the second planetary gear set and the ring gear member of thefirst planetary gear set with at least one of the sun gear member of thethird planetary gear set and the ring gear member of the secondplanetary gear set, the third clutch is selectively engageable tointerconnect at least one of the sun gear member of the third planetarygear set and the ring gear member of the second planetary gear set withat least one of the planet carrier member of the first planetary gearset and the input member, the first brake is selectively engageable tointerconnect at least one of the sun gear member of the first planetarygear set and the sun gear member of the fourth planetary gear set withthe housing, and the second brake is selectively engageable tointerconnect the ring gear member of the fourth planetary gear set withthe housing.
 35. The transaxle of claim 34 wherein the first clutch isdisposed in the second area, the second clutch is disposed in the fourtharea, the third clutch is disposed in the sixth area, the first brake isdisposed in the first area, and the second brake is disposed in thefirst area.